This invention relates to a method of encapsulating an electrical component.
An electrical component, and in particular an elongate component such as an electrical conductor, including a bus bar, and connections, or joints, therebetween, may be encapsulated, for electrical insulation and/or sealing purposes for example, in several different ways. Heat recoverable polymeric sleeves, in tubular or wraparound configuration and optionally having an adhesive or mastic inner coating, are now well known and widely accepted for this purpose, and offer significant advantages over other methods in a large number of applications. Insulating by means of a push-on arrangement, whilst not requiring any heat source, is restricted, for any given sleeve, to a substrate of a size within a very small range of values if adequate sealing thereto is to be achieved. Insulating by tape wrapping does overcome the last-mentioned difficulty, but care has to be taken to ensure complete covering of the substrate and thus adequate protection. However, it is known to apply around a cable joint a tape that has, immediately prior to wrapping on to the substrate, been coated with a mixed two part curing resin. The resin is arranged to flow over the whole of at least the outermost surface of the wrapped tape, thus filling any gaps, but this can be messy and thus unpleasant and awkward to handle. Furthermore, wrapping a narrow tape, possibly in more than one layer, around a substrate, can be very time consuming.
However, there are instances where encapsulation is required in which it may be impossible or inconvenient to use sleeves that are recoverable by heat or by any other means, and in which tape wrapping as described above may not be convenient.
Examples of such instances are a hazardous area, where a flame cannot be used, an area where flammable material is in close proximity, or a confined area, where access is not conveniently available all around the substrate to be encapsulated, and where the component to be encapsulated is of inconveniently irregular shape. It may be possible in such instances to encase the component within two interlocking half shells that are subsequently filled with a hot pourable material that solidifies and cures on cooling, but this itself is inconvenient and bulky, and does not give good control of the encapsulant thickness, for example for insulation purposes. Furthermore, up to twenty four hours, or even longer, may have to be allowed for the liquid encapsulant to cure fully before the enclosed electrical component may be made fully operational.
It is an object of the present invention to provide a method of encapsulating an electrical component or other substrate that overcomes, or at least alleviates, at least some of the above-mentioned disadvantages.